The Multi-Output Quantum Pulse Gate: a Novel High-Dimensional QKD Decoder

With the development of quantum computers, classical cryptography for secure communication is in danger of becoming obsolete. Quantum cryptography, however, can exploit the laws of quantum mechanics to guarantee unconditional security independently of the computational power of a potential eavesdropper. An example is quantum key distribution (QKD), which allows two parties to encrypt a message through a random secret key encoded in the degrees of freedom of quantum particles, typically photons.